Atypical meningioma: a retrospective analysis of six cases and literature review

Abstract

Background: Atypical meningiomas (AM) are WHO grade II tumors with high heterogeneity and invasiveness, which are unique in their clinical presentation, imaging, pathology, treatment, and prognosis. In 2016, the diagnosis of AM remodified by the classification of central nervous system tumors of World Health Organization (WHO). In order to further analyze the diagnosis and treatment characteristics of AM, the clinical diagnosis, surgery treatment and follow-up data of 6 patients with AM in our hospital from January 2016 to December 2019 were analyzed retrospectively. Methods: The clinical diagnosis, treatment and follow-up data of six patients with AM admitted to our hospital between January 2016 and December 2019 were analyzed retrospectively, and related literature was reviewed.Results: The main clinical symptoms of the patients were increased intracranial pressure and functional area symptoms. MRI showed obvious enhancement, an unclear boundary with adjacent brain tissue, a large edema signal shadow in the white matter of peripheral brain tissue, and rapid enlargement in some cases.Pathological manifestations showed local necrosis and increased nuclear division activity. The results of immunocytochemistry showed that vimentin and epithelial membrane antigen (EMA) were positive, S-100 protein (S-100) and glial fibrillary acidic protein (GFAP) were negative, and the Ki-67 proliferation index was increased. Simpson's grade I-II resection was performed in five cases and no recurrence found after 4 to 46 months of follow-up. Simpson's grade IV resection was performed in one case and no follow-up was performed after discharge.Conclusions: AMs are highly heterogeneous and invasive. Histologic diagnosis is the gold standard for diagnosis and surgical resection is the first treatment choice. Total resection (Simpson I-II) helps to reduce recurrence.

Intracranial meningiomas at a tertiary hospital: Spectrum of MRI findings with histopathologic correlation

“…Meningiomas have a strong female predominance, which is also documented in this study, as well as in retrospective South African-based case reviews of 52 meningiomas by Fynn et al,38 cases by Vivier et al and 48 cases by…”

“… 37 They most characteristically show facilitated diffusion with increased signal on the ADC map 37 ; this study case did not show significant diffusion facilitation or restriction. An isolated WHO Grade II atypical variant was encountered; these lesions classically show heterogenous T1-WI and T2-WI signal intensity, prominent enhancement, significant perilesional oedema and a poor plane of separation from adjacent brain tissue; 38 however, this study case did not demonstrate any of these suspicious features, but instead showed a circumscribed, homogenous, solid and well marginated lesion with only mild perilesional oedema. An isolated case of anaplastic meningioma was also present.…”

Clinicopathological characteristics and prognostic factors of atypical meningiomas with bone invasion: a retrospective analysis of nine cases and literature review

“…AMs represent less than one fifth of all meningiomas [ 16 ], and this is the reason why in the literature there are many case presentations, or the analyzed series are not very large [ 17 , 18 ].…”

Clinical application of a three-dimensional-printed model in the treatment of intracranial and extracranial communicating tumors: a pilot study

“…In addition, MRI scans and the 3D-printed model confirmed that the right optic nerve was segmentally embedded in the tumor. Moreover, for this patent, intraoperative frozen-section pathology revealed atypical meningioma, which shows high invasiveness and thus required total resection to promote prognosis [ 19 ]. Owing to all these factors, the affected optic nerve was intentionally removed, which resulted in the loss of eyesight.…”